The present invention relates to a leakproof or waterproof electromagnetic relay.
Miniature relays are increasingly demanded in a leakproof design. This is achieved, for example, by having the rim portion of the cover projecting downwardly below the bottom of the lower housing providing an open cavity or space. The space is sealed with a casting resin while the relay is turned upside down. For an improved distribution of the sealing compound it is known, for example, from published German patent application DE-OS No. 28 51 329 and German petty patent No. 7821 508, to provide the under side of the bottom with a network of grooves extending to the separating points between the housing members and/or between the housing members and the contact terminals. By providing a predetermined amount of pourable sealing compound (casting resin) there is supposed to be obtained a sealed connection at all separating points of the housing parts into which the compound enters due to capillary action.
However, when pouring in the sealing compound from the bottom of the relay, the sealing compound may easily flow through an excessively large opening toward the inside of the housing, thus causing the relay to become unserviceable in certain cases. Moreover, the relay must remain in an inverted position until the sealing compound has hardened.
It is the object of the present invention to make a relay leakproof in a simple way without causing the aforementioned detrimental effects due to a wrong distribution of the sealing compound, thus permitting the relay to be easily further handled after the sealing process.